Teixobactin and iChip

I have finally had the chance to read the Nature article (behind a pay wall) that has been making waves in the recent news, including the Guardian, Forbes and Bloomberg among others. The authors, who are from academic institutions in the USA (Boston) and Germany (Bonn), as well as a drug discovery company from the UK (Selcia, Ongar, Essex, UK), also appear to have formed a pharmaceutical company – NovoBiotic Pharmaceuticals LLC – as a spin off banking on the technology they described in their paper.

Screenshot – Teixobactin and iChip paper in Nature, 2015

Essentially, the paper described a novel antibiotic Teixobactin that was discovered from screening “unculturable” bacteria from soil, using a novel multi-channel device (iChip) that cultivates bacteria in their natural soil environment and permits the screening of their products obtained via diffusion chambers for antimicrobial properties. Teixobactin is produced by a type of Gram-negative bacteria called Eleftheria terrae, which cannot be cultured out using conventional laboratory methods.

Now the antibiotic Teixobactin is in itself fairly unremarkable beyond the fact that it belongs to a novel class of antibiotics. It only works on Gram-positive bacteria and possibly Mycobacteria (i.e. tuberculosis and likely the non-tuberculous mycobacteria or NTM). It does not work against Gram-negative bacteria, which is where the problem of antimicrobial resistance is the most acute, because it is unable to penetrate the outer membrane of such bacteria (this only makes sense, since the organism that produces this compound is also a Gram-negative bacteria). The claim that antibiotic resistance does not develop against this antibiotic will probably not withstand the passage of time, like with all other antibiotics. It is also in the early stage of drug development, and is at least 5-6 years away from being used in clinical care.

However, the methodology and technology that enabled the discovery of this drug is very promising. The majority of currently available antibiotics are derived from soil bacteria (which produce such compounds in order to compete with other soil bacteria in the environment) – and only from those that could be cultured by conventional laboratory methods. We know – from microbiome sequencing – that more than 95% of bacteria in the soil (or in humans/animals for that matter) cannot be cultured out. The iChip, and future iterations or adaptations of such technology, potentially allows us to discover and tap on novel antimicrobial compounds produced by these previously “unculturable” bacteria, which previously could not be detected.